Bass are predominantly sight feeders and rely on their vision to locate prey. However, their sense of smell often first alerts them to the presence of a nearby meal. (Photo courtesy of Pure Fishing)
October 12, 2023
By Craig Buddo
The debate about whether it’s worth applying scent to bass lures and soft plastics has been raging for decades. Results from testing done by scientists and researchers vary depending on who is doing the research. Test-tank results often seem contradictory to actual on-the-water experiences. Mix in a bit of folklore and a sprinkling of overly optimistic marketing promotion, and you’re left with a confusing, malodorous mist. Let’s try to cut to the quick here.
DR. SCENT Dr. Keith A. Jones, the former Director of the Berkley Fish Research Center literally wrote the book on the subject: “Knowing Bass: The Scientific Approach to Catching More Fish” (Lyons Press, 2002). Though unfortunately now out of print, the book is still the standard reference material for understanding the science behind bass senses and behavior, and how to use that information to improve bass fishing success—whether using Berkley products or not.
Dr. Jones, considered the top expert on fish olfaction, wrote in his Ph.D. dissertation at Texas A&M that there is a huge genetic diversity among gamefish. Bass are unique predators, and understanding how they use their senses to hunt is key to gaining confidence with scent.
Baits with realistic scent and taste encourage bass to not only strike, but also hold the lure longer, which leads to better hookup success. (Photo courtesy of Pure Fishing) It’s well understood that bass are primarily sight feeders, but it’s a big mistake to know that and then dismiss their sense of smell and taste. Smell, for example, is the sole function of their nostrils and is the only one of the bass’ senses with a direct path to the brain, all others being processed to some extent. That alone should tell you it’s important to them.
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NEED TO FEED Dr. Jones lays out in his book that bass are in a more neutral state when holding near cover or suspending. They aren’t constantly scanning their surroundings looking for prey; they’re powered down in something akin to a mental fog.
If a positive food scent washes into a bass’ nostrils for a long enough period, in a strong enough concentration to separate itself from all the other scent in the water, it can begin to wake the bass from its idling state.
If you’re now visualizing the bass pushing forward to sniff out the source of the scent trail like a bloodhound, you need a re-think. Scent in lakes and ponds doesn’t disperse in anything like a straight line, it slowly blooms out and mushrooms and is pushed around by current. In addition, a bass’ nostrils are only a small distance apart, making it difficult for them to locate smells directionally. They’re also unable to gauge how recent or fresh a smell is.
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Alerted to the possibility of a meal close by, they begin to wake from their torpor and then switch to their most developed sense—their acute eyesight. They scan the environment around them with their wide peripheral vision, looking for the possible food source. If the water is murky or dark, they’ll use whatever combination of senses they can for location.
If the bass is able to lock onto the food item, it may simply accelerate towards it and strike, bypassing any other sensory assessment. Bass can be ferocious feeders, but they often proceed much more cautiously. It all depends on their hunger level or whether the prey item is slower moving or behaving erratically.
As it tracks its target, the bass will use all its senses, including smell, to analyze the attractiveness of the potential meal. If it doesn’t pass the “smell test,” the strike will frequently be called off. If it passes that test and doesn’t trigger any other alarms, the bass will approach closer or make contact.
The taste system now kicks in. Humans only have taste buds on our tongues; bass have them on their lips, throughout their mouths, down their throat and even on their gills. The initial contact may only be a bump or very quick nip, or the item might be sucked loosely into the front of the mouth while it undergoes a more focused taste and “mouthfeel” test. Bass don’t even need to make physical contact, as they can taste food in the literal sense from a short distance away, as water flows across the taste buds in the mouth and gills.
If everything checks out, the food item is taken into the mouth and passed to the last set of taste buds in the throat for a final sign-off before swallowing. If it fails either the mouth or throat taste test, a bass can eject the item within about a quarter of a second.
After attraction, the primary benefit of realistic scent and taste applied to a bass lure is that it encourages the bass to hold the bait in its mouth just that little bit longer.
GOTTA BE MEATY Jones categorizes this smell-taste feeding sequence as arousal, attraction, assessment and acceptance. But what are the smells and tastes we can apply to our lures that are most likely to fool bass into following the path to acceptance and a successful hookset?
Logically, a baseline for any successful scent or flavor should be derived from the things that bass normally like to eat.Dr. Jones says in his book, "Bass are predators. They eat meat, mostly prey fish, crayfish and other aquatic prey, although as opportunistic feeders they will take just about any small animal that comes their way. As such, they savor a wide variety of meaty flavors, especially those high in protein."
Not on that list, note, is anything sweet, peppery or vegetable-based; no anise (licorice oil), no salt or garlic. That isn’t to say those flavors can’t provide a valuable masking function, helping to neutralize otherwise repellant chemical and contaminant smells and tastes, but the science indicates they aren’t effective “attractants.”
This was studied at Berkley and more recently at Queen’s University in Ontario, Canada, in the lab of Dr. Bruce Tufts, Professor of Fisheries and Conservation. Dr. Tufts’ lab was contracted by American Baitworks to develop an effective bass attractant based on scientific data. After reviewing all the previously published literature and conducting more than 5,000 videotaped tank tests, they came up with a formula that was released by the company last year called BaitFuel.
BaitFuel JUST RIGHT Dr. Connor Elliott, who was then a graduate student under Dr. Tufts, conducted the majority of those tests and is confident that BaitFuel can improve fishing results. Creating something that attracts bass and stimulates their sense of taste, as opposed to a simple masking agent, is no small undertaking, though.
"The most important thing when trying to mimic natural prey items in artificial baits is identifying which components are providing stimuli to the predator fish," says Dr. Elliott. "There are a lot of compounds that can be found in natural prey items that don’t actually provide any benefit and act as ‘filler’ in an artificial scent. Once the proper compounds are identified, the next challenge is determining the correct ratio of these components. If too much of some of these compounds are added, they can be overstimulating for the fish and actually become detrimental."
Not only does the formula have to attract bass, it also has to be effectively applied to the lure. It’s the original sticky design problem. The solution should ideally be quick-acting and highly water soluble to dispense the most scent into the water. It also must be slow-acting and gummy enough to stay on the lure and convince the bass to hold onto it. If we accept that no lure or solution can completely achieve both of those aims, we can start to think about scent in a more strategic fashion.
There might be situations where water solubility to achieve the widest field of positive food signals is the best approach—for instance, murky water or a small bay that could be thoroughly seeded with attractive scent through repeated casting. And there might be times when bass have no problem locating a lure visually but are just bumping it or short-striking. A scent-infused bait chosen for its mouthfeel and taste might be what gets a fish to commit. Or maybe you double up, with an infused bait and a water-soluble dip.
No matter what your opinion of scents may be, extensive research and observation have shown that they can help draw more strikes when bass turn tight-lipped. And at the very least, they certainly cannot hurt.
SWEET SCENTS These products promise to help you catch more fish. Berkley PowerBait MaxScent flatworm (top), Pro-Cure trophy bass super gel (left) and Bass Assassin Bang. Several companies add scent to their soft plastics or offer spray-on additives for masking and attraction. These include Big Bite Baits, Z-Man, SPRO and Bass Assassin among others. Here are a few products from companies that have taken a deep dive into the science of scent and bass attraction.
Berkley’s PowerBait MaxScent (berkley-fishing.com ) is incorporated into a wide range of its soft plastics, with the standout product being the Flatworm, now the company’s best-selling softbait. Mark Sexton, the current head of Berkley’s fish lab, says the design goal for MaxScent was to combine the best scent and flavor elements of PowerBait and Gulp! with advances in material science to maximize scent dispersion and taste/texture without sacrificing durability or ease of use.
Pro-Cure (pro-cure.com ) has spent 20 years developing successful products primarily for West Coast and Great Lakes salmon and trout anglers, though the company also offers scent products for largemouth and smallmouth bass. The scent products are mostly blends of natural food items developed in-house that have been tested extensively by a roster of pro anglers. Trophy Bass Super Gel came out in 2004 and is a mix of threadfin shad, crawfish, minnow (Tui chub) and nightcrawler.
Bass Assassin (bassassassin.com ) uses a unique rendering process to produce natural, concentrated oils of prevalent bass forage species for its Bang spray . The special formulation is advertised to draw more strikes and make fish hold onto the bait longer than baits bot treated with an application of Bang.
